Biggest upsets on WTA Tour 2025: Boisson incredible Roland Garros showing, Vondrousova victory over world number one, Eala historic Miami run

Tennis is used to seeing regular upsets, especially in big tournaments such as Grand Slam events. The highest ranked players go into it targeting deep runs just to get knocked up by someone ranked outside the top 300. This has happened twice on the WTA Circuit to the same player in the biggest upsets of 2025.

Jessica Pegula came to the Canadian Open in search of a third consecutive title. She started well, defeating Maria Sakkari in straight sets. This set her up with the world number 386 Anastasija Sevastova in the round-of-32. However, it was not as simple as it looked on paper. The Latvian, formerly ranked 11th in the world back in 2018, caused a seismic shock in Montreal, defeating the American 3-6, 6-4, 6-1.

Despite only playing 24 Tour level matches in four years, Sevastova managed to find the goods to dump out the heavy favourite in the tie. She finished a fine performance by sweeping up the final six games, and eight of the last nine to send her charging through to the last-16.

This was not even the first time an event had occurred like this for Pegula in this calendar year. The number seed heading into Roland Garros, it looked like a routine round-of-16 tie against home favourite Lois Boisson. The Frenchwomen had been entered as a wildcard for the event, looking to make her nation proud and to clinch some key ranking points. She did this in fine style, dumping out Pegula 3-6, 6-4, 6-4.

She did not let a poor end to the first set get the better of her. While it was almost a certainty that Pegula would run away with it, Boisson had other ideas. She levelled up proceedings ahead of a hectic last couple of games where Pegula missed numerous opportunities to sieze the advantage. Boisson took hers and famously sealed a maiden Grand Slam quarter-final. She would go on to defeat the number six seed Mirra Andreeva before being overpowered by the eventual champion Coco Gauff.

Marketa Vondrousova has tumbled down the rankings due to injury after an unexpected title at Wimbledon. Nevertheless, she proved that run on grass was no fluke as she storfmed to the title in the Berlin Open. Enroute, she disposed of the world number one Aryna Sabalenka 6-2, 6-4.

The Czech star shot up the rankings after this triumph. While it may not be classed as the biggest upset to lose against someone with her calibre, the ranking says otherwise in a damaging defeat to Sabalenka. However, she would get her revenge in Cincinnati before Vondrousova encounted more injury woes returned ahead of their US Open quarter-final clash, giving the Belarusian a free pathway through.

Now ranked number 11 in the world, some may find it hard to remember how far down the order Belinda Bencic was at the start of the year. Due to stepping away from the sport in 2024 as she became a mother for the first time, her ranking plummeted ahead of a highly anticipated return in 2025. This climb up the rankings was kicked off by winning the Dubai Championships. On the way to the title, she defeated the number five ranked player in the world Elena Rybakina 3-6, 6-3, 6-4.

After very closely fought first two sets where just a break separated the pair, the Swiss star took the advantage in the third and deciding set. She clinched a double-break lead before squandering two match points on her serve. Two games later, the wildcard confirmed victory for a huge upset.

Alexandra Eala burst onto the scene in a jubilant Miami Open run. Enroute to a stunning semi-final, she defeated the reigning Australian Open champion Madison Keys 6-4, 6-2 before once more producing the goods against six-time Grand Slam champion Iga Swiatek 6-2, 7-5.

The then 19-year-old was entered as a wildcard into the event, taking this opportunity gleefully. After eventually wrestling control of the match from Keys, the Filipino won the final four games to firmly announce herself on the main stage. Her victory in the quarter-final against Swiatek also helped that case. In a match featuring more 13 breaks of serves in 20 games played, Eala was the one to take the advantage. In another world Pegula would have featured on this list again, but she managed to fend off Eala in a three-set clash in the semi-final.